Sofa



FIG. 1 is an elevated perspective view of a sofa showing my new design;

FIG. 2 is a front plan view thereof;

FIG. 3 is a top plan view thereof; and,

FIG. 4 is a side plan view thereof, the opposite side being a mirror image of the side shown.

The rear view is plain and unornamental. 

The ornamental design for a sofa, as shown and described. 